Tuesday, 21 May 2013

Delta Levee Innovations

Since working on the Economic Sustainability Plan with Dr. Pyke, I have been promoting “fat” seismically resistant levees for the Delta as a cost-effective solution to the Delta problem. Now UC-Berkeley engineers are developing even more creative solutions for seismically resilient levees.

In the basement of Davis Hall, Hamed Hamedifar (Ph.D.’12 CEE) is rattling scale models of levees on a shake table, subjecting them to vibrations replicating the magnitude 6.9 El Centro earthquake of 1940. Hamedifar is designing a plate pile system, rectangular plates affixed to three-yard beams, to bolster the strength of levees in places like the California Delta…For one of his research projects, Hamedifar borrowed a technique of using plate piles to prevent landslides that was invented by Richard Short, a geoengineering lecturer at the college and Hamidifar’s mentor, and adapted it for embankments and levees. “It is a very reliable method—cost-effective, environmentally friendly and proven to work,” says Hamedifar…Hamedifar estimates that stabilizing levees with plate piles will save time and money…The average plate pile installation would require 10 days from permitting to finished product, and would cost less than $1 million…In repeated tests, levees with the plate piles showed no deformation post-shaking. Without the plate piles, the levees failed, dropping three to four feet. “It is an exact model of what we are doing but scaling it down for levees,” said Short. “There is a lot of science to scaling it down and doing those tests. The uniqueness is the seismic stability.”

$1 million per mile! Wow, that suggests you could seismically reinforce the Delta levees for under $1 billion, even cheaper than the $2-4 billion we estimated in the DPC economic sustainability plan.

“Richard Short and I made presentations to both the California Department of Water Resources and the U.S. Army Corps of Engineers,” Hamedifar says. “We asked for feedback, but they had no complaints, couldn’t point out any flaws in the technology. But it was clear they weren’t interested—they were obviously determined to focus on another solution.” That kind of tunnel (or Twin Tunnels) vision probably won’t resolve the Delta’s dilemma, Hamedifar says. “It’s always risky to push just one solution for an engineering problem like this, especially if the idea being pushed isn’t demonstrably better than other ideas,” he says. “It’s likely you’ll need a multitude of approaches, not just one. The Tunnels will involve huge fiscal and environmental costs, and they’ll take years to complete. Our approach is cheap and effective, and it can be done quickly. We think it at least deserves a fair hearing.”

Sounds familiar.

Regardless of your preferred technology towards a more seismically resilient Delta (I still like the wide crown benefits of fat levees where there is room), it is worth mentioning yet again that seismic levee upgrades have not only lower costs than the tunnels, but higher benefits. They will save lives! And they will protect critical energy, transportation, and local water infrastructure. They will protect property and agriculture. And yes, they will also protect export water supplies from catastrophic failure.

The state should be dedicating its resources to developing levee technology and alternative water supply technology, instead of the twin tunnels. These technological solutions help everyone, and many have potential applications to solve problems around the world.

BDCP is a failure. It’s time for fresh thinking and innovation.

About the Author

Ethan Jacob

Author & Editor

I am Ethan Jacob Executive Director of the Center for Business and Policy Research at the University of the Pacific, where I have a joint faculty appointment in the Eberhardt School of Business and the Public Policy Program in the McGeorge School of Law..